Problem with Apex cloth

I have this weird problem with an imported hair mesh. The animation and PhysX cloth simulation looks fine in 3DS Max. The hair model is made up of three meshes. One for the ponytail, one for the hair around the head, one for the strands in the forehead and then one for the hairband. I’ve only painted the ponytail and the strands with cloth, so the resulting .apx contains two submeshes which sounds pretty much right to me.

The problem is that the cloth simulation only works in UE for the strands in the forehead. When I try to se the ponytail to simulate, it just disappears. The only thing I can think of is that it says Simul Vertex = Shared on the Apex information in UE. Whereas the submesh for the strands acually has a number. What am I doing wrong? I’ve been going over the Cloth modifier in 3DS Max a hundred times but I can’t find any option that suggests that I’m painting “shared” vertices? Any help or suggestions would be most appreciated!